Applying tsume to characters causes the space around them to be compressed proportionally. However, the vertical and horizontal scaling of the characters remains unchanged.
You can also check which tsume or tracking was applied for each character by highlighting the affected text.
One way in which you can compress aki between characters is to specify the line spacing for the frame grid itself and adjusting tracking for placed text. This is a form of character compression that uses a feature called Adjust Tracking With CJK Grid in the Character panel menu or the Control panel (also called grid tracking).
Some characters in CJK fonts are smaller than the embox, resulting in a large aki between characters when they are placed on the frame grid. Setting tsume in this way for the grid itself is convenient because it allows mojikumi where characters are properly aligned in the grid. This setting can also be saved as a grid format.
The Character Aki default in the Frame Grid Settings dialog box is set to “0”. In automated typography, this tracking is known as “Beta”. Setting this to a negative value for mojikumi causes the right grid to overlap the left grid in accordance with the set value. Characters input to the grid will be aligned on the basis of the center of the each grid, so the spacing for each character will be compressed. In addition, depending on the mojikumi settings, character forms adjusted to less than the maximum width will change on the basis of the value proportion of Line Spacing Tsume. For instance, when mojikumi is set to half spacing for yakumono such as parentheses, by setting the Character Aki in the grid to ‑1H, yakumono will be compressed to half of ‑1H, thus ‑0.5H. However, because character spacings based on tracking in this grid are not applied to Roman text, character spacing for Roman text will not be compressed in line with tracking. In addition, because this tracking value is applied to the grid itself, it is handled as an absolute value. For this reason, even if the text font size changes, the tracking value does not.
This feature is enabled by default. To disable this feature, select Adjust Tracking With CJK Grid from the Character panel menu or Control panel, and deselect the box to the left of the item name.
You can justify text for specified grid characters by setting grid jidori. For example, if you select 3 characters entered and set jidori to 5, the 3 characters will be spread evenly across the grid for 5 character spaces.
Use the Grid Jidori feature in the frame grid. It may not function properly in a text frame.